Surgical weight loss has become the most effect treatment for the severely obese patient. By 2020, it is estimated that at least 13% of the U.S. population will be eligible for the procedure (BMI > 40 kg/m2). Recent studies have highlighted the importance of regular exercise for positive surgical outcomes. Exercise may have a number of benefits post-surgery, such as attenuating the muscle and bone loss that accompanies massive, rapid weight loss. We have assembled a team of experts in bariatric surgery and exercise promotion in severely obese people and people with conditions limiting physical activity to develop and test a pilot exercise program adapted to the needs of persons who have undergone bariatric surgery. This program builds upon an effective 12 week intervention our team developed and tested for adults with arthritis: Fitness for People with Arthritis (FEPA). Severely obese individuals often have conditions such as osteoarthritis, which limit their mobility and participation in exercise programs, making FEPA a sound foundation for the development of a safe and effective program for them. This program is also ideal for post-bariatric patients in that it focuses on all aspects of fitness (strength, flexibility, and endurance) without an emphasis on body weight. We will further adapt FEPA specifically to the bariatric population, which has had difficulty adopting and adhering to regular exercise in the past, by including progressive exercise goals across a longer period of time (six months instead of 12 weeks), using a mastery learning approach to achieving these goals, adding a maintenance phase with booster exercise sessions and social support, and integrating the program into the regular post-operative care. Our goals are to determine effective strategies for initially recruiting post-bariatric surgery patients into randomized studies on group exercise, determine factors affecting program attrition over a one year period for participants in the intervention group and measurement attrition over the same period of time for participants in both control and intervention groups, and determine the acceptability and appropriateness of the exercise intervention for post-bariatric patients including what level of exercise can be sustained by this population. With the completion of these aims, we will apply for funding from the NIH to conduct an efficacy trial to provide the evidence that we will need to translate our program into the standard of care for persons in the first year after bariatric surgery. This will provide the crucial empirical evidence needed to integrate functional fitness programs into best practices for the long-term health care of persons after bariatric surgery.